1. Field of the Invention
The present invention relates to a wireless communication system.
2. Description of the Related Art
Scheduling schemes used in a wireless communication system include centralized scheduling schemes and distributed scheduling schemes. In a centralized scheduling scheme, one control node such as a base station schedules radio resources of other nodes. In a distributed scheduling scheme, each node randomly selects its radio resource. The distributed scheduling scheme mostly adopts a contention-based method, and a plurality of distributed nodes fundamentally occupies the radio resources through adequate contention. An example of a well-known distributed scheduling scheme includes a Carrier Sense Multiple Access (CSMA)/Collision Avoidance (CA) scheme.
Fairness and maximum system throughput are major criteria of the scheduling. The fairness reflects how fairly each node occupies the resource, and the maximum system throughput reflects how efficiently the whole system is utilized.
There is trade-off between the fairness and the maximum system throughput. Accordingly, when the maximum system throughput is focused more, the fairness between the nodes is not ensured to thus cause resource starving of a particular node. Conversely, when the fairness is focused more, each node fairly occupies the resource but the whole system throughput can be degraded. Hence, it is necessary to fulfill the effective distributed scheduling by considering both of the fairness and the maximum system throughput.
Therefore, a need exists for an apparatus and a method for distributed scheduling by guaranteeing fairness and considering system throughput at same time in a wireless communication system.
The above information is presented as background information only to assist with an understanding of the present disclosure. No determination has been made, and no assertion is made, as to whether any of the above might be applicable as prior art with regard to the present invention.